BRITISH LEYLAND 1B4428 Nos Engine Rebound Buffers BN1-BJ8

( Brand: British Leyland ), ( Manufacturer Part Number: 1B4428 ), ( Type: Mount Rebound Buffer ), ( Vintage Part: Yes ), ( Universal Fitment: No ), ( Placement On Vehicle: Front ), ( Country Of Origin: United Kingdom )

Review BRITISH LEYLAND Nos Engine Mnt Rebound Buffers Austin Healey

The **British Leyland 1B4.428 NOS (New Old Stock) engine rebound buffers** for the Austin Healey 100/6 series spanning models from the **BN1 (1953) through to the BJ8 (1967)** represent a critical yet often overlooked component essential for maintaining the precise valvetrain dynamics and longevity of this legendary British sports car s classic pushrod engine. These rebound buffers, typically crafted from high-grade **cast iron or steel**, are designed to absorb and dissipate the recoil energy generated by the camshaft s lobes as they drive the rocker arms and pushrods during the engine s operation. In the context of the **1B4.428**, a robust and reliable inline-six powerplant renowned for its smoothness and durability, these buffers play a pivotal role in preventing excessive valvetrain noise, reducing wear on the rocker arms and pushrods, and ensuring consistent valve timing all of which are vital for preserving the engine s performance and character. The **NOS (New Old Stock) specification** of these buffers guarantees that they are either original or meticulously restored to factory condition, free from modern aftermarket modifications that could compromise the engine s authenticity or performance. Whether sourced from a **disassembled BN1 s valvetrain** or a carefully preserved BJ8 s components, these buffers embody the engineering precision of the era, where every detail from the machined surfaces to the precise fitment was optimized for both performance and reliability. For the discerning owner or restorer of an Austin Healey, investing in genuine NOS rebound buffers is not merely a matter of function but a homage to the craftsmanship that defined these cars legendary status, ensuring that the engine s timeless charm remains intact for generations to come.

### **Pros and Cons of Buying a British Leyland 1B4428 (Nose Engine) with MNT Rebound Buffers for an Austin Healey BN1-BJ8**

The **1B4428** engine, originally developed by **BMC (British Motor Corporation)** and later produced by **British Leyland**, was a refined version of the earlier **1B4426** and **1B4427** units. It was commonly used in **Austin Healey BN1-BJ8** models, particularly in the **BN1 (1967-1969)** and **BN2-BJ8 (1969-1973)** series. When fitted with **MNT (Modified Natural Timing) rebound buffers**, this engine offers a balance of performance and reliability, though it comes with trade-offs.

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### **Pros**

1. **Proven Reliability (When Maintained Properly)**

- The **1B4428** is a robust inline-six engine, known for its durability in classic British sports cars when kept in good condition.

- With **MNT rebound buffers**, the engine s valve train is less prone to catastrophic failure compared to stock timing chains, which were notorious for stretching or breaking.

- Many examples have lasted **100,000 miles** with regular maintenance, especially if the **camshafts, lifters, and timing chain** are kept in good order.

2. **Better Performance Than Stock (With MNT Modifications)**

- **MNT (Modified Natural Timing)** refers to a **non-interference camshaft** setup with **rebound buffers** (also called "valve springs") that prevent valve-to-piston contact in the event of a timing chain failure.

- This modification **reduces the risk of bent valves** if the timing chain slips, making the engine safer to drive without constant monitoring.

- Some owners report **slightly improved breathing** due to the modified camshaft profile, though gains are modest compared to full performance cams.

3. **Easier to Source Parts Than Later BL Engines**

- Unlike later **British Leyland** engines (e.g., **2.0L or 2.6L units**), the **1B4428** has a **longer production run** (1967-1973), meaning **gaskets, seals, and minor components** are still relatively accessible.

- **BN1-BJ8 engines** were built in sufficient numbers that **replacement parts** (e.g., **camshafts, lifters, timing chains**) are not as rare as those for later Austin Healey models.

4. **Classic Healey Character**

- The **1B4428** retains the **smooth, mid-range torque** that made early Austin Healeys beloved.

- With **MNT rebound buffers**, the engine remains **drivable even if the timing chain fails**, avoiding the risk of a **bent-valve disaster** that plagued many stock BN1-BJ8s.

5. **Potential for Modifications**

- The engine can be **tuned for better performance** (e.g., **ported heads, upgraded carburetors, or mild camshaft swaps**).

- **MNT setups** are often used as a **compromise** enough safety to drive without constant worry, but still capable of **modifications** if desired.

6. **Lower Cost Than Later Healey Engines**

- Compared to **later Austin Healey engines (e.g., 2.0L or 2.6L units)**, the **1B4428** is generally **cheaper to buy and repair**.

- **BN1-BJ8 engines** are less expensive than **3000GT or Sprite engines**, making them a **more budget-friendly** classic Healey option.

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### **Cons**

1. **Timing Chain Reliability Still a Concern**

- While **MNT rebound buffers** reduce the risk of **bent valves**, the **timing chain itself can still stretch or break** over time.

- **Regular inspection (every 30,000-50,000 miles)** is **essential** many owners recommend **replacing the chain and sprockets** as a precaution.

- A **failed timing chain** can still cause **engine damage** (e.g., **bent lifters, damaged camshaft lobes**), though not as catastrophic as bent valves.

2. **Maintenance Requirements Are High**

- **Valve clearances** must be checked and adjusted **every 6,000-10,000 miles**.

- **Lifters** wear out and may need **replacement or lapping**.

- **Rebound buffers (MNT springs)** can **lose tension** over time, reducing their effectiveness.

- **Neglect leads to expensive repairs** this is not a "set-and-forget" engine.

3. **Fuel and Emissions Challenges**

- The engine was **not designed for modern fuels** **lead-free gasoline** can cause **valve seat recession** and **carbon buildup**.

- **SU carburetors** (common in BN1-BJ8s) require **regular cleaning and adjustment** to run smoothly.

- **Emissions compliance** is difficult many owners **modify or remove catalytic converters**, which may not be legal in all regions.

4. **Potential for Hidden Issues**

- **BN1-BJ8 engines** were built in a **transition period** between BMC and British Leyland, meaning **quality control varied**.

- **Leaking oil seals** (crankshaft, camshaft).

- **Worn cylinder head gaskets** (leading to **coolant leaks or compression loss**).

- **Rod bearings** that can **wear out** if the engine was not maintained.

- A **pre-purchase inspection (PPI) is strongly recommended** many engines have **silent failures** (e.g., **low compression, oil leaks**) that aren t obvious to the untrained eye.

5. **Limited Aftermarket Support Compared to Modern Classics**

- While **BN1-BJ8 parts are available**, they are **not as widely supported** as **later Austin Healeys (e.g., 3000GT)** or **modern classics (e.g., MGB, Triumph TR6)**.

- **Specialist mechanics** who work on **1B4428 engines** are **less common**, making repairs **more expensive or time-consuming**.

6. **Driving Experience Can Be Unpredictable**

- Even with **MNT rebound buffers**, the engine **lacks the refinement** of later **2.0L or 2.6L Austin Healey engines**.

- **Vibration** (especially at higher RPM) can be **notable**, particularly in **BN1 models** (later BN2-BJ8s were slightly improved).

- **Throttle response** is **not as snappy** as modern or tuned examples expect a **more laid-back** driving experience.

7. **Resale Value Is Moderate**

- While **BN1-BJ8s with 1B4428 engines** have a **dedicated following**, they are **not as valuable** as **fully restored or rare examples**.

- **Engines in poor condition** can **devalue the car significantly** buyers often **pay more for a known-good engine**.

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### **Conclusion**

The **British Leyland 1B4428 engine with MNT rebound buffers** in an **Austin Healey BN1-BJ8** offers a **compromise between reliability and performance**. It is **safer to drive than a stock BN1-BJ8** (thanks to the **MNT modification**), but **still requires diligent maintenance** to avoid **timing chain or valve train issues**.

- **Enthusiasts who want a drivable, modifiable classic Healey** without the constant fear of **bent valves**.

- **Those who enjoy working on engines** and are willing to **budget for regular upkeep**.

- **Budget-conscious buyers** who want a **BN1-BJ8 without the highest repair costs** of later models.

- **Casual drivers** who want a **low-maintenance, set-and-forget** classic car.

- **Those who prioritize modern comfort and reliability** over vintage charm.

- **Buyers who cannot commit to frequent inspections and minor repairs** (e.g., **lifter adjustments, chain checks**).

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### **Recommendation**

If you are **serious about owning an Austin Healey BN1-BJ8 with a 1B4428 engine**, follow these steps to **maximize your chances of a trouble-free experience**:

1. **Buy from a Reputable Seller**

- Look for **engines with a documented service history**, preferably **with recent timing chain and lifter checks**.

- **Avoid engines that have had multiple owners** this often indicates **neglect or hidden problems**.

2. **Get a Full Pre-Purchase Inspection (PPI)**

- **Compression levels** (should be **consistent across all cylinders**).

- **Oil

Details:

You are buying on a New Old Stock British Leyland PAIR of Engine Mount Rebound Buffers for Austin Healey 100-4, 100-6, and 3000 BN1 through BJ8 cars. The Buffers are in mint condition the Original British Leyland bags.The Austin, BMC, Leyland, and Uni part number is 1B4428.

part #: 1b4428 prices

• $20.00-$113.06

specifications engimou:

• for makes: Austin, Healey
• brand: British Leyland
• mpn: 1b4428
• type: Mount Rebound Buffer
• vintage part: Yes
• universal fitment: No
• placement on vehicle: Front
• country of origin: United Kingdom

seller engimou:

• # reviews: 14000
• city: North Haven, Connecticut
• rating: 100.0%

payments engimou:

• wallet: Paypal
• other
• credit card: Discover

general engimou:

• condition: New
• Car Truck Parts Accessories > Engines Engine Parts > Engine Mounts

returns engimou:

• policy: Returns Accepted
• time: 30 Days
• paid by: Seller

offer engimou:

• started: February 15, 2026
• options: Ship-to-home
• availability: In Stock
• quantity: 1
• sold: 0

shipping engimou:

• carrier: USPS
• type: Calculated
• class: Standard
• service: USPS Ground Advantage
• transit: 17-20 Days
• cost: $11.05

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